Merge pull request #587 from AbhigyaKrishna/main

Encoding and Decoding case insensitive enums
charleskorn · Aug 11, 2024 · 098d578 · 098d578
2 parents ad48c20 + d13223f
commit 098d578
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Showing 3 changed files with 43 additions and 4 deletions.
diff --git a/src/commonMain/kotlin/com/charleskorn/kaml/YamlConfiguration.kt b/src/commonMain/kotlin/com/charleskorn/kaml/YamlConfiguration.kt
@@ -18,6 +18,8 @@
 
 package com.charleskorn.kaml
 
+import kotlinx.serialization.ExperimentalSerializationApi
+
 /**
  * Configuration options for parsing YAML to objects and serialising objects to YAML.
  *
@@ -35,6 +37,7 @@ package com.charleskorn.kaml
  * * [sequenceBlockIndent]: number of spaces to use as indentation for sequences, if [sequenceStyle] set to [SequenceStyle.Block]
  * * [allowAnchorsAndAliases]: set to true to allow anchors and aliases when decoding YAML (defaults to `false`)
  * * [codePointLimit]: the maximum amount of code points allowed in the input YAML document (defaults to 3 MB)
+ * * [decodeEnumCaseInsensitive]: set to true to allow case-insensitive decoding of enums (defaults to `false`)
  */
 public data class YamlConfiguration(
     internal val encodeDefaults: Boolean = true,
@@ -52,6 +55,8 @@ public data class YamlConfiguration(
     internal val allowAnchorsAndAliases: Boolean = false,
     internal val yamlNamingStrategy: YamlNamingStrategy? = null,
     internal val codePointLimit: Int? = null,
+    @ExperimentalSerializationApi
+    internal val decodeEnumCaseInsensitive: Boolean = false,
 )
 
 public enum class PolymorphismStyle {

diff --git a/src/commonMain/kotlin/com/charleskorn/kaml/YamlScalarInput.kt b/src/commonMain/kotlin/com/charleskorn/kaml/YamlScalarInput.kt
@@ -42,13 +42,20 @@ internal class YamlScalarInput(val scalar: YamlScalar, yaml: Yaml, context: Seri
             return index
         }
 
-        val choices = (0..enumDescriptor.elementsCount - 1)
+        val choices = (0..<enumDescriptor.elementsCount)
+            .asSequence()
             .map { enumDescriptor.getElementName(it) }
-            .sorted()
-            .joinToString(", ")
+
+        if (configuration.decodeEnumCaseInsensitive) {
+            val idx = choices.indexOfFirst { it.equals(scalar.content, ignoreCase = true) }
+
+            if (idx != -1) {
+                return idx
+            }
+        }
 
         throw YamlScalarFormatException(
-            "Value ${scalar.contentToString()} is not a valid option, permitted choices are: $choices",
+            "Value ${scalar.contentToString()} is not a valid option, permitted choices are: ${choices.sorted().joinToString(", ")}",
             scalar.path,
             scalar.content,
         )

diff --git a/src/commonTest/kotlin/com/charleskorn/kaml/YamlReadingTest.kt b/src/commonTest/kotlin/com/charleskorn/kaml/YamlReadingTest.kt
@@ -274,6 +274,33 @@ class YamlReadingTest : FlatFunSpec({
                     }
                 }
             }
+
+            context("parsing case insensitive enumeration value") {
+                val yaml = Yaml(configuration = YamlConfiguration(decodeEnumCaseInsensitive = true))
+
+                test("deserializes it to the expected enumeration value") {
+                    val result = yaml.decodeFromString(TestEnum.serializer(), "value1")
+
+                    result shouldBe TestEnum.Value1
+                }
+
+                test("deserializes explicit names to the expected enumeration value") {
+                    val result = yaml.decodeFromString(TestEnumWithExplicitNames.serializer(), "with SPACE")
+
+                    result shouldBe TestEnumWithExplicitNames.WithSpace
+                }
+
+                test("throws exception with case sensitive configuration") {
+                    val exception = shouldThrow<YamlScalarFormatException> { Yaml.default.decodeFromString(TestEnum.serializer(), "value1") }
+
+                    exception.asClue {
+                        it.message shouldBe "Value 'value1' is not a valid option, permitted choices are: Value1, Value2"
+                        it.line shouldBe 1
+                        it.column shouldBe 1
+                        it.path shouldBe YamlPath.root
+                    }
+                }
+            }
         }
 
         context("parsing null values") {